# NTSB SEA98LA013: Bell 206B, N101LF, Forest Grove, OR, November 8, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 8, 1997, 12:20 local (20:20 UTC) - Place: Forest Grove, OR - Coordinates: 45.550525, -123.150299 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.5505&lon=-123.1503&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 4, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 42735 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42735/pdf - Page: https://openairdocs.org/ntsb/SEA98LA013 ## Probable cause Excessive deceleration of the helicopter by the pilot-in-command, resulting in an in-flight main rotor blade strike on the helicopter's external load line and subsequent main rotor separation. Downhill terrain which led to a descending approach to the pickup point was a factor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - terrain condition - downhill (contributing factor) - maneuver - excessive, pilot in command (cause) - external load cable/hook - blade strike - rotor system,main rotor - separation - In flight collision with terrain/water, descent - uncontrolled ## Analysis The helicopter was approaching a pick-up area for a load of Christmas trees. The approach was over a tree-lined ridge and down into a basin. The pilot reported that while decelerating, he heard a loud bang. Warning horns and lights went off as the helicopter turned to the left and rolled right, subsequently colliding with trees and terrain. A witness on the ground stated that as the helicopter was descending, the long line swung forward and straight up in front of the cabin. The main rotor blades instantly separated and the helicopter started to descend. The witness heard a loud screaming sound, then a loud explosion, and observed the helicopter come apart in mid-air. The cabin continued in the same direction that it was traveling and turned up-side down and collided with trees and terrain. The tail section separated and collided with terrain near where the witness was standing. Cable marks were found on one main rotor blade and one tail rotor blade. The load line itself was severed from the helicopter, and the load line hook displayed severe impact damage signatures. ## Factual narrative On November 8, 1997, at 1220 Pacific standard time, a Bell 206B, N101LF, registered to Hillsboro Helicopters, Inc. of Hillsboro, Oregon, was observed to break up in midair and descend in an uncontrolled manner to a collision with the terrain while performing a 14 CFR Part 133 rotorcraft external-load flight near Forest Grove, Oregon. Visual meteorological conditions prevailed at the time. The commercial pilot-in-command was not injured, and the helicopter was destroyed in the accident and an ensuing post-crash fire. The flight had departed Hillsboro, about three hours prior to the accident. The Federal Aviation Administration (FAA) reported no record of a flight plan having been filed for the flight. In a written statement, the pilot reported that he was returning to the pick-up area for another load. The pilot stated that he was approximately 50 feet above ground level and traveling between 40 and 50 mph when he began the deceleration process. The pilot pulled power back and heard a loud "bang." The pilot stated that warning horns and lights went off as the helicopter turned to the left and rolled right, subsequently colliding with the trees and terrain. A witness on the ground reported that he was waiting for the helicopter to return for another load and observed the helicopter fly over a ridge line in preparation to descend into the basin. The witness stated that 15 to 16 foot trees lined the ridge. When the helicopter was about 120 yards away from his position, he saw the long line cable and bell swing forward and shoot straight up in front of the cabin. The witness stated that the main rotor blades instantly separated and the helicopter started to descend. The witness heard a loud "screaming" sound, then a loud explosion and observed the helicopter come apart in mid-air. The cabin continued in the same direction that it was traveling and turned up-side down and collided with trees and the terrain. The tail section separated and collided with the terrain near where the witness was standing. An FAA inspector from the Portland Flight Standards District Office, Hillsboro, Oregon, responded to the accident scene and reported the following findings to the NTSB investigator-in-charge (IIC). The inspector reported that he observed extensive damage to one main rotor blade, cable marks on the other main rotor blade, one severed tail rotor blade with cable marks, and that the load line itself was severed from the helicopter. The inspector also reported that the hook on the load line displayed severe impact damage signatures. ## Aircraft - Registration: [N101LF](https://openairdocs.org/deregistered/N101LF-1998-08-07), registration cancelled 1998-08-07, S/N 2663 (OpenAirDocs) - Reported make and model: Bell 206B - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Category: Helicopter - Serial number: 2663 - Airframe hours: 6547 - Engines: Allison 250 C20B 420 horsepower turbo shaft - Damage: Destroyed - Fire: On-Ground - Flight: Other work use, Part 133 - Registered owner: Hillsboro Helicopters Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 26, 1997, 100 hours before - Departed: HIO, HILLSBORO, OR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 4,230 total, 1,630 in this make and model, 4,140 as pilot in command, 59 in the last 90 days, 21 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 7 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 50 °F, dew point 46 °F - Altimeter: 30.00 inHg - Observed at: HIO, 6 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19971108032629A](https://openairdocs.org/incident/19971108032629A), Nov 8, 1997: Bell 206B, Forest Gorve, OR, Destroyed. Long line cable swung up in front of 206 decelerating to pick up another load. 206 broke up struck trees and burned. (.19) on November 8, 1997, at 1220 pacific… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.